全文获取类型
收费全文 | 139篇 |
免费 | 11篇 |
出版年
2022年 | 4篇 |
2021年 | 6篇 |
2020年 | 2篇 |
2019年 | 4篇 |
2018年 | 3篇 |
2017年 | 4篇 |
2016年 | 5篇 |
2015年 | 12篇 |
2014年 | 12篇 |
2013年 | 15篇 |
2012年 | 7篇 |
2011年 | 8篇 |
2010年 | 6篇 |
2009年 | 9篇 |
2008年 | 6篇 |
2007年 | 6篇 |
2006年 | 5篇 |
2005年 | 2篇 |
2004年 | 6篇 |
2003年 | 7篇 |
2002年 | 5篇 |
2001年 | 1篇 |
2000年 | 3篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1991年 | 1篇 |
1969年 | 3篇 |
排序方式: 共有150条查询结果,搜索用时 15 毫秒
111.
Angela Terezinha De Souza Wyse João José Freitas Sarkis João Sabino Cunha-Filho Marcio Vieira Teixeira Maria Rosa Schetinger Moacir Wajner Clovis Milton Duval Wannmacher 《Neurochemical research》1994,19(9):1175-1180
The in vitro effects of phenylalanine and some of its metabolites on ATP diphosphohydrolase (apyrase, EC 3.6.1.5) activity in synaptosomes from rat cerebral cortex were investigated. The enzyme activity in synaptosomes from rats subjected to experimental hyperphenylalaninemia (-methylphenylalanine plus phenylalanine) was also studied. In the in vitro studies, a biphasic effect of phenylalanine on both enzyme substrates (ATP and ADP) was observed, with maximal inhibition at 2.0 mM and maximal activation at 5.0 mM. Inhibition of the enzyme activity was not due to calcium chelation. Moreover, phenylpyruvate, when compared with phenylalanine showed opposite effects on the enzyme activity, suggesting that phenylalanine and phenylpyruvate bind to two different sites on the enzyme. The other tested phenylalanine metabolites (phenyllactate, phenylacetate and phenylethylamine) had no effect on ATP diphosphohydrolase activity. In addition, we found that ATP diphosphohydrolase activity in synaptosomes from cerebral cortex of rats with chemically induced hyperphenylalaninemia was significantly enhanced by acute or chronic treatment. Since it is conceivable that ATPase-ADPase activities play an important role in neurotransmitter (ATP) metabolism, it is tempting to speculate that our results on the deleterious effects of phenylalanine and phenylpyruvate on ATP diphosphohydrolase activity may be related to the neurological dysfunction characteristics of naturally and chemically induced hyperphenylalaninemia. 相似文献
112.
Freire M Neto MS Garcia EB Quaresma MR Ferreira LM 《Plastic and reconstructive surgery》2007,119(4):1149-56; discussion 1157-8
113.
Fernandez RC Ottoni CA da Silva ES Matsubara RM Carter JM Magossi LR Wada MA de Andrade Rodrigues MF Maresma BG Maiorano AE 《Applied microbiology and biotechnology》2007,75(1):87-93
Seventeen different strains of filamentous fungi were grown in batch cultures to compare their abilities for the production
of β-fructofuranosidase. Three of them, Aspergillus oryzae IPT-301, Aspergillus niger ATCC 20611 and strain IPT-615, showed high production with total fructosyltransferase activity higher than 12,500 units l−1. In addition, the β-fructofuranosidases of those strains have a high fructosyltransferase activity-to-hydrolytic activity
ratio. The temperature and pH effects on the sucrose-β-fructofuranosidase reaction rate were studied using a 22 factorial experimental design. The comparative analysis of the tested variable coefficients shows that the variable pH contributes
mostly to the changes in the fructosyltransferase and hydrolytic rates and in the V
t/V
h ratio. At 40 and 50°C, there were no significant differences between the fructosyltransferase and hydrolytic velocities of
these enzymes. 相似文献
114.
De Souza AM Carvalho TL Sabino PM Vives D Fontes CF Lopes AG Caruso-Neves C 《Biochimie》2007,89(11):1425-1432
We show that MDCK I cells express, besides the classical (Na(+)+K(+))ATPase, a Na(+)-stimulated ATPase activity with the following characteristics: (1) K(0.5) for Na(+) 7.5+/-1.5 mM and V(max) 23.12+/-1.1 nmol Pi/mg per min; (2) insensitive to 1 mM ouabain and 30 mM KCl; and (3) inhibited by furosemide and vanadate (IC(50) 42.1+/-8.0 and 4.3+/-0.3 microM, respectively). This enzyme forms a Na(+)-stimulated, furosemide- and hydroxylamine-sensitive ATP-driven acylphosphate phosphorylated intermediate with molecular weight of 100 kDa. Immunoprecipitation of the (Na(+)+K(+))ATPase with monoclonal anti-alpha(1) antibody reduced its activity in the supernatant by 90%; the Na(+)-ATPase activity was completely maintained. In addition, the formation of the Na(+)-stimulated, furosemide- and hydroxylamine-sensitive ATP-driven acylphosphate intermediate occurred at the same magnitude as that observed before immunoprecipitation. These data suggest that Na(+)-ATPase and (Na(+)+K(+))ATPase activities are independent, with Na(+)-ATPase belonging to a different enzyme entity. 相似文献
115.
Raquel Sabino Elisabete Carolino Richard B. Moss Niaz Banaei Cristina Verissimo David A. Stevens 《Mycopathologia》2017,182(9-10):863-867
Candida albicans is a common microbe, colonizer and potential pathogen found in respiratory cultures of cystic fibrosis (CF) patients. Because of possible development of resistance in patient isolates resulting from residence in the abnormal milieu of CF patient airways, or from exposure to antifungals, and considering the possibility of patient-to-patient spread of microbes and reports of elevated resistance to other fungal pathogens, it was important to assay the susceptibility of isolates of Candida and compare that profile to isolates from the community. In our center, and unlike another fungal pathogen, no increase in resistance of Candida isolates of the CF cohort was found. 相似文献
116.
Bruno Oliveira de Figueiredo Brito Zachi I. Attia Larissa Natany A. Martins Pablo Perel Maria Carmo P. Nunes Ester Cerdeira Sabino Clareci Silva Cardoso Ariela Mota Ferreira Paulo R. Gomes Antonio Luiz Pinho Ribeiro Francisco Lopez-Jimenez 《PLoS neglected tropical diseases》2021,15(12)
BackgroundLeft ventricular systolic dysfunction (LVSD) in Chagas disease (ChD) is relatively common and its treatment using low-cost drugs can improve symptoms and reduce mortality. Recently, an artificial intelligence (AI)-enabled ECG algorithm showed excellent accuracy to detect LVSD in a general population, but its accuracy in ChD has not been tested.ObjectiveTo analyze the ability of AI to recognize LVSD in patients with ChD, defined as a left ventricular ejection fraction determined by the Echocardiogram ≤ 40%.Methodology/principal findingsThis is a cross-sectional study of ECG obtained from a large cohort of patients with ChD named São Paulo-Minas Gerais Tropical Medicine Research Center (SaMi-Trop) Study. The digital ECGs of the participants were submitted to the analysis of the trained machine to detect LVSD. The diagnostic performance of the AI-enabled ECG to detect LVSD was tested using an echocardiogram as the gold standard to detect LVSD, defined as an ejection fraction <40%. The model was enriched with NT-proBNP plasma levels, male sex, and QRS ≥ 120ms.Among the 1,304 participants of this study, 67% were women, median age of 60; there were 93 (7.1%) individuals with LVSD. Most patients had major ECG abnormalities (59.5%). The AI algorithm identified LVSD among ChD patients with an odds ratio of 63.3 (95% CI 32.3–128.9), a sensitivity of 73%, a specificity of 83%, an overall accuracy of 83%, and a negative predictive value of 97%; the AUC was 0.839. The model adjusted for the male sex and QRS ≥ 120ms improved the AUC to 0.859. The model adjusted for the male sex and elevated NT-proBNP had a higher accuracy of 0.89 and an AUC of 0.874.ConclusionThe AI analysis of the ECG of Chagas disease patients can be transformed into a powerful tool for the recognition of LVSD. 相似文献
117.
Giuseppe Aiello Cosimo Sabino Davide Pernici Matteo Audano Francesco Antonica Matteo Gianesello Claudio Ballabio Alessandro Quattrone Nico Mitro Alessandro Romanel Alessia Soldano Luca Tiberi 《EMBO reports》2022,23(9)
Lifespan is determined by complex and tangled mechanisms that are largely unknown. The early postnatal stage has been proposed to play a role in lifespan, but its contribution is still controversial. Here, we show that a short rapamycin treatment during early life can prolong lifespan in Mus musculus and Drosophila melanogaster. Notably, the same treatment at later time points has no effect on lifespan, suggesting that a specific time window is involved in lifespan regulation. We also find that sulfotransferases are upregulated during early rapamycin treatment both in newborn mice and in Drosophila larvae, and transient dST1 overexpression in Drosophila larvae extends lifespan. Our findings unveil a novel link between early‐life treatments and long‐term effects on lifespan. 相似文献
118.
119.
120.
Claudia Rodríguez-Almazán Luis Enrique Zavala Carlos Mu?oz-Garay Nuria Jiménez-Juárez Sabino Pacheco Luke Masson Mario Soberón Alejandra Bravo 《PloS one》2009,4(5)